Large numbers of used toner cartridges from printers and photocopiers have become a significant issue in office environmental protection throughout the world, and it is feasible to recycle the used toner cartridges and reuse them. Many manufacturers have refilled used toner cartridges with toner and then re-sealed them for reuse, thereby reducing the environmental pollution arising from the discarded toner cartridges used in printers and duplicators. In the process of reusing and re-processing the used toner cartridges, the sealing method is different from that of an OEM. When making brand-new toner cartridges by OEMs, the toner chamber slots are sealed using adhesives and by heating and pressure. However, in the case of reprocessing used toner cartridges for reuse, the common practice is to seal the toner chamber slot using high-performance double sealants to tightly adhere the sealing material to the peripheral edges around the toner chamber slot.
There exist some disadvantages in the conventional technology in terms of the sealing strips used by OEMs for sealing the original toner cartridges and those used for sealing the recycled old toner cartridges in the recycling sector, as well as the manufacturing methods thereof. The Chinese Patent Application Publication No. CN1224861, published on Aug. 4, 1999 disclosed a sealing component, a process cartridge, and a developer supply container. The disclosed sealing component is used as the sealing strip for sealing toner cartridges, including (horizontally) a sealing portion, an elongated portion as well as the edges for connecting the sealing portion to the elongated portion, and vertically (in thickness) a surface layer, a laser beam blocking layer, a guide layer fusible by laser beams, and a sealing layer for adhering the sealing component to the toner cartridge slot. The sealing portion is provided with a tearable portion that can be torn, around the edges of which there are holes to form guide lines. These holes are shaped by the partially fused guide layer by laser beams on the sealing component. This sealing component is complicated in the processing process. Additionally it is unable to make the tearable portion have a width equal to the elongated portion (in practice, an equivalent width is the ideal status) due to the limitation to the processing technique. Thus, connection has to be made by means of connecting edges with a specific shape. The manufacturing process for this kind of sealing components is as follows: First, laser beams are projected onto the sealing component's blanks using a laser device to make guide lines consisting of many holes on the guide layer. Then, the sealing component's blanks are placed into a die, with multiple sealing components made by die stamping. The disadvantages of this technique includes: (1) a laser device is expensive and highly costly, and the cost becomes more prohibitive for the small lot production; (2) two separate devices are needed for forming guide lines by laser scanning and the die stamping of the sealing component's external contour, therefore increasing the manufacturing cost, and (3) it is also impossible to obtain relatively higher precision (hence making the elongated portion unable to have a width equal to the guide lines, accordingly connecting edges are needed for connection).
The foregoing-described sealing components are used by OEMs for sealing the original toner cartridges. In addition, there are also some sealing components used for sealing used toner cartridges in the recycling sector, e.g. the sealing strip disclosed in U.S. Pat. No. 6,041,202 (filed on Jul. 6, 1999, and issued Mar. 21, 2000), and China Patent No. ZL01266096.5 (filed on Nov. 19, 2001, and issued on Jul. 31, 2002). The sealing material used in these sealing strips is a type of non-woven fiber ribbon material, which is strenuous to tear and hard to form openings with consistent width when being torn (e.g., the torn sealing strip may become broadened, narrowed or obliquely pulled, or become laminated due to offset, or have low opening precision).
Therefore, it would be desirable to provide an improved sealing strip for sealing a toner chamber slot of a toner cartridge and its manufacturing process.